insect

American Heritage® Dictionary of the English Language, Fourth Edition

1. n. Any of numerous usually small arthropod animals of the class Insecta, having an adult stage characterized by three pairs of legs and a body segmented into head, thorax, and abdomen and usually having two pairs of wings. Insects include the flies, crickets, mosquitoes, beetles, butterflies, and bees.
2. n. Any of various similar arthropod animals, such as spiders, centipedes, or ticks. See Regional Note at lightning bug.
3. n. An insignificant or contemptible person.

Century Dictionary and Cyclopedia

1. n. A small, usually winged and many-legged, invertebrate creature whose body appears to consist of several segments: a term used in popular speech without exactitude, being applied not only to flies, fleas, dragon-flies, butterflies, moths, bees, wasps, crickets, grasshoppers, roaches, beetles, bugs, lice, and other familiar creatures properly called insects, but also, improperly, to other small creatures whose structure and relations are not popularly understood, as the so-called coral insect, which is an actinozoan.
2. n. In zoology, any member of the class or other division of animals called Insecta; an arthropod; a condylopod; an articulated animal with articulated legs, especially one with six such legs; a hexapod. See Insecta and Hexapoda, 1.
3. Of, pertaining to, or of the nature of an insect or insects: as, insect transformations; insect architecture.
4. Like an insect in any respect; small; mean; contemptible.
5. To seek or catch insects, as a bird does.

Wiktionary

1. n. An arthropod in the class Insecta, characterized by six legs, up to four wings, and a chitinous exoskeleton.
2. n. Any small arthropod similar to an insect including spiders, centipedes, millipedes, etc
3. n. A contemptible or powerless person.

GNU Webster's 1913

1. n. One of the Insecta; esp., one of the Hexapoda. See insecta.
2. n. Any air-breathing arthropod, as a spider or scorpion.
3. n. Any small crustacean. In a wider sense, the word is often loosely applied to various small invertebrates.
4. n. Fig.: Any small, trivial, or contemptible person or thing.
5. adj. Of or pertaining to an insect or insects.
6. adj. Like an insect; small; mean; ephemeral.

WordNet 3.0

1. n. small air-breathing arthropod
2. n. a person who has a nasty or unethical character undeserving of respect